This means your flash player has crashed. This can happen if you're using an old version of Flash player, require a graphics card update or don't have enough CPU/RAM resources available.
Try shutting down programs that you are no longer using and closing any browser tabs which are no longer required.
Check that Flash player is up to date: http://get.adobe.com/flashplayer
If you continue to experience this issue please submit a support request and we'll be in touch.